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I've not read the whole thing (it's 44 pages!) but Yu Lu is, IMO, doing the Right Thing in this field - he takes a Semi Analytic Model of galaxy formation, and *actually fits* all the parameters to the data (in this case, the observed K-band luminosity function). Some parameters are well-constrained (implying we may have learnt something about galaxies), while others show strong degeneracies, indicating what new physics needs to be included. Seems like the models in most of the parameter volume fail to predict some other datasets, giving more clues on how to improve the model. The key thing is that by doing the inference properly, Lu has elevated SAM study to a quantified learning process.

This looks like it might be interesting - new optical spectra and Spitzer IR data for 4 galaxies at z=2 show that the dust in these systems is rather different than in the local universe. The high magnification provided gravitational lenses arranged in front of them helped a lot!

Well, alright it just looks like SMC dust instead of MW dust but still, cool that we can measure it in galaxies at z=2!

Hezaveh et al simulate ALMA cycle 1 (ie 0.16" resolution) observations of Herschel/SPT sub mm lensed galaxies, and claim that the magnification is high enough, and the sources likely to be complex enough, to enable the detection of at least one DM subhalo of mass 10^8 or greater *in every system*

Astrophysics > Cosmology and Extragalactic Astrophysics Title: Large-Scale Structure with Gravitational Waves I: Galaxy Clustering (Submitted on 7 May 2012) Abstract: Observed angular positions and redshifts of large-scale structure tracers such as galaxies are affected by gravitational waves through volume distortion and magnification effects.

Combining galaxy distribution / clustering measurements with weak lensing shear measurements is a hot topic at the moment and this is the latest attempt to use both to reconstruct the COSMOS density field.

Astrophysics > Cosmology and Extragalactic Astrophysics Title: First measurement of the bulk flow of nearby galaxies using the cosmic microwave background (Submitted on 6 Jul 2012) Abstract: Peculiar velocities in the nearby Universe can be measured via the kinetic Sunyaev-Zel'dovich (kSZ) effect.

The authors claim a detection of a missing dark satellite in a galaxy-galaxy strong lens system B1938+666. The claimed perturber is located at the brightest region in the lensed image.

Boylan-Kolchin et al identify a new problem with CDM at sub-galactic scales: the Aquarius simulated MW galaxy halos have subhalos that are about 5 times more massive than the actual dwarf satellites we see. Are we underestimating the MW satellites' masses somehow? Or is their something wrong with the simulations? Or both? Anyway, as Phil B said: add it to the list of things to investigate about CDM :-)

The observational counterpart? http://arxiv.org/abs/1111.2611

Interesting: Strigari & Wechsler prefer to state the problem as the sims predicting 25-75 times as many subhalos at the Fornax mass scale as are observed in the MW system - and in the paper you posted they look at thousands of MW analogs in the SDSS survey and find that the MW is not atypical. This strengthens MBK's conclusion, that there is a problem with CDM - although note that S&W put the emphasis on galaxy formation not being well understood at this mass scale. They imagine that there really are all those dark Fornaxes out there! Pretty cool - now, if we could just see them somehow...

Suyu et al combine strong gravitational lensing and stellar kinematics data for a spiral galaxy to measure the mass of both the disk and the dark matter halo. The constraints are very strong - they find an oblate, flattened halo, and get a disk stellar mass with small uncertainty (0.1dex); when they compare this with the stellar mass from the disk colours and K-band magnitude they find that stellar population models with Chabrier IMF work, and Salpeter does not - the opposite to the case of massive elliptical galaxies.

Kelly and Kirshner look at the SDSS images and spectra of the host galaxies of more than 500 nearby supernovae. Seems like an interesting complement to the SNLS host studies, I'd be interested to hear from Mark where this one fits. They can resolve the galaxies very well, so can make statements like "the SN Ic-BL and SN IIb explode in exceptionally blue locations" :-)

Authors: Lado Samushia,Beth A. Reid,Martin White,Will J. Percival,Antonio J. Cuesta,Lucas Lombriser,Marc Manera,Robert C. Nichol,Donald P. Schneider,Dmitry Bizyaev,Howard Brewington,Elena Malanushenko,Viktor Malanushenko,Daniel Oravetz,Kaike Pan,Audrey Simmons,Alaina Shelden,Stephanie Snedden,Jeremy L. Tinker,Benjamin A. Weaver,Donald G.

Discovery of a very distant group of galaxies believed to be living in a M > 10^14 solar mass halo.

"Observations of lensing of the 21-cm background from the dark ages will be capable of detecting M>~10^12 Msun/h mass halos, but will require futuristic experiments to overcome the contaminating sources."

There is a discrepancy between cluster Y_SZ measurements made by Planck and AMI. Yikes!

They claim a ~100x speed increase when using GPUs over a single processor. Execution time on the GPUs is comparable with a 128-processor MPI implementation.

Deason et al have an improved measurement of density and velocities of blue horizontal branch stars in the MW halo: here they fit dynamical models an infer a halo of about 1e12 Msun (as before) and quite a high concentration (cvir~20). Since concentration reflects age, this is consistent with the picture in which the MW has been undisturbed for a long time.